A magnetic disk (herein after will be called simply as a disk) used for recording information is inspected by an inspection apparatus with regard to such as defects of the surface and whether the performance of the recording medium is good or bad. Such inspection apparatus takes out successively a disk from a cassette, which accommodates a plurality of disks not yet inspected and representing inspection objects, fits the taken out disk to a spindle of the inspection apparatus and rotates the same. Then, for the first time, the front face side of the disk is inspected, after completing the inspection, the disk is inverted and the back face side thereof is inspected and the disk completed the inspection is accommodated into another cassette used for already inspected disks. In order to transfer a disk between both cassettes for not yet inspected disks and for already inspected disks and the spindle and to invert the same efficiently, the inspection apparatuses of this sort are provided with a variety of transfer devices using a robot mechanism. Among these, U.S. Pat. No. 5,909,117 (which corresponds to JPH10-143861A) discloses a disk inspection apparatus in which a plurality of spindles are disposed on a turn table, an inspection stage and a disk inverting mechanism are arranged around the turn table, the turn table is rotated by a predetermined angle and disks are inverted thereby, the front and back faces of the disks are successively inspected.
An application of a hard disk device (HDD) spreads now a days such as to automotive products, home appliance products and audio products, hard disk drive devices for from 2.5 inches to 1.8 inches, moreover for below 1.0 inch are built-in in a variety of devices and used therefor. The size of the hard disk drive devices tends to be further reduced, moreover, a unit cost of the hard disk drive device itself decreases and manufacturers are required to manufacture a great quantity of hard disk drive devices while reducing the cost.
For this reason the disk inspection apparatus is also demanded to inspect a great quantity of disks efficiently and to reduce the size thereof. However, although the conventional disk inspection apparatuses including one disclosed in U.S. Pat. No. 5,909,117 as referred to above can process successively many number of small sized disks below 2.5 inches, because of the use of the turn table, a variety of devices such as the inspection stage and sthe disk inverting mechanism have to be arranged around the disk turn table, therefore, a problem remains that in comparison with the size reduction of the disks representing the inspection objects, the size reduction of the inspection apparatus is insufficient.